Device for bending tubes



June 16, 1931. G, A. BRYAN DEVICE FOR BENDING TUBES Filed April 23, 1929 MMM ATTORNEY INVENTOR 'faff//f/AM 30 invention;

Patented June 16, 1931 ;y Y

A burma: starsxsf rArfENr ,asics GEORGE A.,BRYAIBL OF PERU, INDIANA', ASSIGNOR TO RYAN SVTEAM CORPORATION,

` A' CORPOliet'IONk 0F. NEW MEXICO. 'Y

:DEVICE FOR BENDING-.TUBES Y Appncationzied April 2e, 192e. semi No. 357,432.

By my. invention, I contemplatea device for bending tubes as, for example, the water tubes of a watertube boiler'sucli as that disclosed in Letters Patent No. 1,672,480,

granted 'to rneJ une 5, 1928. y c l 1n forming tubes by bending,y as isdone in water tube boilers and water heaters such as those kuse d in domestic orhome heating systems, great care must be ltakento bend the [tube Without constricting the cross-sectional area thereof. @ne objectof my invention'is to produce adeviceby means of which such tubes maybe quickly and accurately bent into shape andthereby -decrease the time required, and consequently the expense of producing these coils. 1 ,c f In accordance with my invention,V I provide a bed-plate to which a stationary arcuate f swaging block `is secured, and a movable swaging block ywhich acts inail positions of its movement at a tangent to the curved edge of the stationary block. The moving,

tangential swa/ging block presses the tube against the stationary block and 'forces the tube to conform to the curvature thereof.

A detail description of one embodiment kof my invention will be given in connection with the accompanying drawings in' which:

f yFig. 1 is a plan of a device embodying my Fig. 2 is an end elevation of the device shown in Fig.y 1,v and L f Fig. 3 is a section on the' line Vof Fi .1. l' ln the. illustrated. embodimenuvwhich is thetype used for shaping copperv tubing to be usedin a water tube boiler such as that which isused in domesticheating systems, there is a bed-plate 1 to .which a stationary swaging block oranvil 2is secured by means vof machine screws 3. -The stationary swagking block has converging edges 11 and 5 and an arcuate inner end 6, the center of which l is .coaxial with they center of'the bed-platel 1. A continuous .semi-circular'y groovel is` formed v,inthe edges ,4 and v5 and the arcuate end @of the swaging block or anvil 2.,.The groove is :inclined to and crosses allongi tudinal central :plane parallel tothe sides of 5 the swaging block and containing the'cenfin the edge of the swaging tliereof, is positioned to cooperate with the means of bolts 23.

tral laxis thereof. `The groovestarts in the converging edge adjacent the face or side of the swagingV block in contact with the bed-platek 1, runsv at an angle to the longitudinal central `plane of the block, crosses the plane yat the arcuate end 6 and terminates adjacent .the outer side of the swaging block at the end of the converging edge 5. Tlf he purpose of the inclination of the groove block will appear as the description proceeds. Y

Secured to and in sliding `contact with the base plate 1, a clamping block 7 having a com,- plementary semicircular groove in one edge edge 4 of the swaging block 2. The clamping block 7 is pressed into engagement with the edge fl ofthe stationary Vswaging block 2 by a cam S having a' handle 9 secured thereto and pivotedwithin a bifurcated casting 10 having iianges 11 through which it is secured to the bed plate 1 by means of bolts 12.

A hand` lever 13 substantially T-shape in planis pivoted at one end of thefiange 111 coaxial with the center yof, the arcuateI endk of the stationary swaging blQACk 2. Thus,-the hand levery 13 rotates about the central axisof the arcuate endof the stationary swaging block as a tangent to a circle having a radius equal to the length of the arm 174. On the surface of the flange 14, a. block` 15 having a bifurcated flange -16 is adjustably secured by means of abolt 1T engaging the sidesof a and is adapted to press upon a U-shape block i 19 which carries a roller 20journale`dbetween the. sides of the VU. rEhe U-shape block 19has on the side adjacent lthe surface of the flange 111, extensions 21 which are slidably engaged Y by side plates `22 secured to theflangey 14 by The roller 2O bears' on one edge of almovable swaging bloclr24t nearV one end thereof. 'A similar roller 25, secured to the hand'leverfl in a similar manner tob" the roller 20, with the exception that thecani clamping member 1S vand its associated parts are omitted, bears on they other end of the movable swaging block 24. Below? the roller 25, the swagingblock 24 issecured-to the. c

f there is a slight pivotal movement of the swaging block 24 around the pin 26 and the end of the swaging block 24 under the roller 2O engages `the edge of the stationary swaging block 2 near the arcuate end thereof, and as the hand lever 13 is rotated about its pivot the edge oit the movable swaging block 24 moves as a tangent to the arcuate end of the stationary swaging block 2. rlhe position ofy the rollers 2() and 25 is adjustable by means of the set screws 27 and the lock-nuts 28. A stop member 29 having a slot opened at one edger and an end inclined to the surface thereof, is secured to the hand lever 13 near Vthe hand grip portion thereof, and determines the length to which Aa tube may be inserted in the device. Angle members 30 secured to the side of the hand lever determine the angular relation of the planes containing successive bends iormedr in a tube.

In the construction shown, by turning the tube into Contact with the members 30 after each bend thesuccessive bends in the tube will lie in parallel planes.

Secured to the bed-plate 1, a stop member 31 prevents a backward rotation of the hand lever 13. An arcuate strip 32 which is secured to the edge of the bed-plate 1, acts as a bearing for the hand lever 13 in its rotation about its ivot.

This tulie bending machine is especially applicable to forming the water tubes of a water tube boiler, such as that disclosed in my patent above referred to. Such tubes are bent upon themselves to extend across the combustion chamber. The plane of the successive reverse bends in the tubes are olset, the reverse bends in the tube on one side ot the boiler being in one plane and thel reverse bends in the tubey on the other side of the boiler being contained in a plane parallel to the first but offset therefrom. The operation of the device is as follows:

, A 'tube is inserted along the inclined grooves yin the clamping block 7 and the block 7 perpendicular to the side edge 4 of thestationary swaging block 2 to clamp the tube therebetween, and the cam 18 lmoves the movable swaging block 24 about its pivotal connection 26 to the lever 13 into clamping engagement with the arcuate end 6 of the stationary swaging block 2 and clamps the tube in frictional engagement therewith. The hand lever is then rotated about its pivot, the movable swaging block 24 moving asa tangent to the arcuate end of the stationary swagingblock, until the edge of the Amovable swaging block 24 engages the edge 5 of the stationary swaging block 2. The frietional engagement of the edge of the movable swaging block 24 and the arcuate end of the stationary swaging block 2 causes an inwardly longitudinal movement of the movable swag ing block 24 which is permitted by the rollers 120 and 25, together with the slotted connecy tion of this swaging block 24 with the pin 26. The hand lever is then returned to the inoperative position, the clamping cams 8 and 18 are released, the tube pushed into the dcvice and rotated to engage the angle members 80, the bent end being received within the slot in the stop member and the above operations repeated.

The inclination of the groove in the edge of the swaging block gives to the tube, bent in the device, an offset which is required for certain types of Water tube boilers. It is, however, obvious that the groove may be straight as well as inclined, depending upon the shape to which it is desired that the tube conform.

, It is obvious that various changes may be made in thefillustrated embodiment above particularly described within the principle and scope of my invention as expressed in the means for moving said movable swaging block laterally to the lever' arm and clamping said movable swaging block into frictional engagement with the surface of said arcuate stationary swaging block.

2. A tube bending machine comprising a bed late, a stationary swaging block secured yto t e bed plate, the swaging block having an arcuate end portion, a clamping block cooperating with one edge of the stationary swaging block, means for moving the clamping block perpendicular to the edge of the stationaryswaging-block to clamp a tube therebetween, a lever pivoted coaxially with the arcuate end of the swaging block, a mov able swaging block carried by the lever arm p and havingv alongitudinallyl slidable conblock.

nection therewith, and means for moving one end of the movable swaging block into contact with the arcuate end portion of the stationary swaging block and clamping it into frictional engagement therewith.

3. A tube bending machine comprising ay bed plate, a stationary swaging block secured to kthe bed plate, theswaging block having converging side edges `and an arcuate end portion, a clamping block cooperating with one of the side edges of the stationary swagng block, means'for'moving the clamping block perpendicular to the side edge of the swagingblock to clampza tube therebetween, a lever pivoted coaxially'with the arcuate end of the swaging block, a movable swaging block pivotally connected to said lever vand being movable longitudinally thereof,l and means for moving the' movable swaging block about its pivotalconnection to the lever into engagement with the arcuate end of the sta. tionary swaging block and clamping ,K it inA frictional engagement therewith. n

4. A tube bending machine comprising a bed plate, ay stationary swaging block secured to the bed plate, the swaging block having converging side edges and an arcuate end portion, a clamping block cooperating with one of the side edges of the stationary swaging block, means for movingthe clamping rblock perpendicular to theside edge of the swaging block to clamp a :tube therebetween, a

lever pivoted coaxially with the arcuate end of the swaging block, a movable swaging block pivotally connected to said lever and being movable longitudinally thereof, means v for moving the movable swaging block about itspivotal connection to thelever into engagement with .the arcuate endof thefstationary swaging block and clamping vit in frictional engagement therewith, and a stop member secured to said lever for determin-y f ing the lengthjof the tubeextending beyondy the arcuate end of =the kstationary swaging In witness whereof, I

m si ature.

y gn GEORGE A. BRYAN.

hereuntoy subscribe Y 

